APPLICANT'S ABSTRACT This project will examine how tobacco addiction has influenced a cohort of smokers over their lifetimes. The investigators will analyze an existing data set collected by the Normative Aging Study (NAS) on 2,280 males since 1961. In terms of duration, only the study of British doctors has a longer follow-up period. The NAS has systematically (each 3-5 years) collected among the most detailed biomedical and psychosocial data available. Included is information on smoking status (e.g., amount smoked, years smoked), medical and dental histories (e.g., blood pressure, cholesterol, periodontal condition, causes of death), psychosocial measures (e.g., stress, quality of life) and health-related behaviors (e.g., alcohol consumption, diet). Repeated assessments of smoking status and other risk factors will allow the investigators to avoid problems of misclassification bias and confounding bias present in many previous studies. The central theme involves examining the outcomes which occur to individual smokers over time. They will concentrate primarily on addressing issues which have not been studied in detail previously. They will: a) Characterize the natural history of smoking, by calculating yearly quit rates over the past 30 years, identifying variables and events that predict cessation, examining whether there have been changes in levels of consumption among continuing smokers, and the characteristics of smokers who have been unable to quit; b) Investigate the effects of smoking on disease and death, by examining smoking effects on overall mortality, and disease-specific mortality and morbidity. The investigators will focus on issues about which little is known, such as smoking effects on diabetes, benign prostatic hyperplasia (BPH), osteoarthritis, impotence, and oral health. They will also study why smokers have not benefitted from societal improvements in health noted in the past 20 years; c) Examine the effects of smoking cessation on health outcomes such as coronary heart disease and quality of life. In addition, long-term weight gain after smoking cessation will be assessed and its impact on health determined. Results will: 1) inform the Public Health Service concerning progress made regarding smoking in the past 30 years; 2) suggest treatments needed for certain types of smokers (e.g., those experiencing large weight gains after cessation, those who resisted appeals to quit smoking for the past three decades); 3) provide new information on effects of smoking and smoking cessation on health. Such information may motivate many current smokers to quit; 4) generate hypotheses concerning mechanisms related to the onset of medical conditions (e.g., BPH) about which little is known.